Moneyball changed how every professional sport team is managed

In the early 2000s, Billy Beane — general manager of the Oakland Athletics, one of baseball's poorest teams — used statistical analysis (sabermetrics) to identify undervalued players the market had priced cheaply because it was measuring the wrong things. Players with high on-base percentages were undervalued; flashy stolen-base artists were overvalued. Oakland competed with teams spending three times more on salaries. Michael Lewis's book Moneyball (2003) turned the story into a business parable, and within a decade analytics departments had become mandatory in every major professional sport.

Source: Lewis, Moneyball: The Art of Winning an Unfair Game (2003)